DE102005022310A1 - A method for dynamically determining the peak output torque in an electrically variable transmission - Google Patents

Abstract

A method for determining output torque limits of a powertrain that includes an electrically variable transmission relies on a model of the electrically variable transmission. Combined electric machine torque limitations and engine torque limitations define a transmission operating space. The output torque limits are determined at the limits of the transmission operating room.

Description

CROSS REFERENCE RELATED APPLICATIONS

These Application claims the priority of US Provisional Application Ser. No. 60 / 571,658, filed May 15, 2004, hereby incorporated in its entirety inserted by reference is.

TECHNICAL TERRITORY

The The present invention relates to the control of a vehicle powertrain. Especially The invention relates to real time determinations of output torque constraints an electrically variable transmission in the vehicle.

BACKGROUND THE INVENTION

For the management the input and output torques of various prime movers in hybrid vehicles, mostly internal combustion engines and electrical machines, are different hybrid powertrain architectures known. Series hybrid architectures are commonly powered by an internal combustion engine characterized that drives an electric generator, in turn an electric powertrain and a battery pack electric power supplies. In a series hybrid architecture, the engine is not directly mechanically coupled to the drive train. The electric generator can also operate in an electric motor mode to a for the internal combustion engine To provide starter function while the electric powertrain Can recover braking energy of the vehicle by placing it in a Generator mode works to recharge the battery pack. Parallel hybrid architectures are generally by an internal combustion engine and characterized by an electric motor, both of which are direct have mechanical coupling to the drive train. Conventionally, the powertrain contains a manual transmission that for a wide operating range the required gear ratios provides.

It Electrically variable transmission (EVT) are known by combination the features of both in-line and parallel hybrid powertrain architectures provide infinitely variable transmission ratios. EVTs are with a direct mechanical path between an internal combustion engine and an axle drive unit operable and thus enable a high transmission efficiency and the use of cheaper and less massive electric motor systems. Furthermore are EVTs with a motor operation that is mechanical from the final drive independently is, or in different mechanical / electrical intermediate contributions operable and allow thus infinitely variable transmission ratios high torque, electrically dominated starts, regenerative braking, Idling with the engine switched on and multi-mode operation.

in the Area of vehicle powertrain controls It is known that the torque request of a driver as a System torque command to interpret an output torque for the To effect vehicle driveline. This interpretation and this Command require a relatively simple Control management, by the available engine torque in relation to dominates the current set of operating parameters of a vehicle this relationship is relatively good is understood. In hybrid power transmission trains, the are based on an electrically variable transmission, besides affecting available Motor torque a number of factors the output torque, which can be delivered to the vehicle drive train. It is known in these hybrid power transmission trains the Torque request of a driver as a system torque command to interpret and enable individual subsystem limits dictate the actual output torque. These limitations include z. B. the available engine torque, the available Electric machine torque and the available power of the electric energy storage system. Preferably, the various individual and interactive Restrictions, the one available Output torque of the powertrain affect, understood in the way that output torque commands consistent with this torque availability and these subsystem constraints are.

The available development tools and the available modeling may provide some understanding of the output torque available for a hybrid powertrain based on an electrically variable transmission. However, these techniques are generally on stationary loading limited and neglected the importance of inertial moments of dynamic vehicle conditions including vehicle and powertrain acceleration (engine and electric machine accelerations) on the powertrain. In addition, these techniques are inherently iterative in nature, relying on human intervention to determine which parameters are held constant and by which parameters to resolve. Thus, these techniques are poorly equipped to adapt to real-time dynamic multi-variable vehicle solutions for effective control.

SUMMARY THE INVENTION

One Vehicle powertrain contains a motor, an electrically variable transmission, the at least one Contains electric motor, and a powertrain. The engine is functional with an input coupled to the electrically variable transmission and the powertrain is functional with an output of the electrically variable transmission coupled.

One A method of determining output torque limits of the vehicle powertrain includes determining an acceptable one Electric motor torque operating space and determining input torque limits within this operating room. It will be electric motor torque limits determined at the input torque limits. In addition, will based on the input torque limits and the motor torque limits Output torque limits determined. In accordance with one aspect The invention is the permissible Motor torque operating room determined conservatively to create a torque capacity reservation. In accordance With another aspect of the invention, the input torque limits become based on engine torque limits and electric motor torque limits of the allowable electric motor torque operating space certainly. In accordance with yet another aspect of the invention, the electric motor torque limits as the input torque limits, which are the least limited output torques correspond, determined.

One A method of determining output torque limits of the powertrain includes determining input torque limits as the least restricted the input torques, the given motor torque limits and predetermined electric motor torque limits. A determination is made which of the predetermined electric motor torque limits in the Input torque limits the least restricted Output torques correspond. Then, based on the input torque limits and the given electric motor torque limits that are at the input torque limits the least restricted Output torques, the output torque limits certainly. In accordance with one aspect of the invention, the engine torque limits become in accordance determined with a set of engine operating parameters. The engine operating parameters can stored engine torque limit data sets in a control unit or in a real-time calculation of the engine torque limits be used in a control unit. In accordance with another Aspect of the invention become the electric motor torque limits in accordance determined with a set of electric motor operating parameters. The Electric motor operating parameters can stored electric motor torque limit data sets in one Reference the control unit. Preferably, the motor torque limits become determined conservatively to provide a reservation of electric motor torque capacity.

A method of determining output torque limits of the powertrain includes determining least-restricted input torques limited by an electric motor that correspond to predetermined motor torque limits, and determining engine-limited input torques corresponding to predetermined engine torque limits. The input torque limits are selected as the most limited of the input torques limited by an electric motor and the input torques limited by the motor. Thereafter, the output torque limits are determined to be the least limited output torques corresponding to the input torque limits and the predetermined motor torque limit values. In accordance with one aspect of the invention, the engine torque limits are determined in accordance with a set of engine operating parameters. The engine operating parameters may reference stored engine torque limit data sets in a controller or may be used in a real-time calculation of the engine torque limits in a controller. In accordance with another aspect of the invention, the electric motor torque limits are in accordance with a set determined by electric motor operating parameters. The electric motor operating parameters may reference stored electric motor torque threshold data sets in a control unit. Preferably, the motor torque limits are conservatively determined to provide a reservation of motor torque capacity.

SUMMARY THE DRAWINGS

1 Fig. 3 is a schematic representation of the mechanical equipment of a preferred form of a multiple mode, two-mode, electrically variable compound transmission that is particularly suited to the practice of the present invention;

2 Figure 3 is an electrical and mechanical schematic of a preferred system architecture for the hybrid powertrain disclosed herein;

3 Figure 4 is a graphical representation of various operating ranges with respect to the input and output speeds of the exemplary electrically variable transmission disclosed herein;

4A FIG. 4 is a graph of torque space in the motor torques (Ta and Tb) required for operation in the OPERATING MODE 2 of the exemplary electrically variable transmission 1 Constant battery power (Pbat) lines, constant output torque (To) lines, and constant input Ti lines;

4B FIG. 4 is a graph of torque space in the motor torques (Ta and Tb) required for operation in the OPERATING MODE 1 of the exemplary electrically variable transmission 1 Contains lines of constant output torque (To) and lines of constant input torque Ti;

5 Fig. 12 is a graphical representation of the empirically determined electric motor torque-speed characteristics used in determining the allowable Ta-Tb torque space in accordance with the present invention;

6 Figure 13 is a flow chart illustrating exemplary steps in a set of instructions executed by a computerized control unit, particularly with respect to the dynamic determination of peak output torque, in accordance with the present invention;

7 - 10 12 are graphical representations of various steps and their results relating to the dynamic determination of the peak output torque in the Ta-Tb torque space in accordance with the present invention;

11A and 11B illustrate characteristic relationships between engine torque, speed and power loss;

12 FIG. 5 is a flowchart illustrating exemplary steps in an instruction set executed by a computerized control unit, particularly relating to the dynamic determination of peak output torque in accordance with the present invention; FIG.

13 FIG. 5 is a flowchart illustrating exemplary steps in an instruction set executed by a computerized control unit, particularly relating to the dynamic determination of peak output torque in accordance with the present invention; FIG.

14 - 19 12 are graphical representations of various steps and their results relating to the dynamic determination of the peak output torque in the Ta-Tb torque space in accordance with the present invention; and

20 FIG. 12 is a schematic block diagram of a final decision that is performed on various output torques corresponding to parameter limited maximum and minimum output torques with respect to the dynamic determination of peak output torque in accordance with the present invention.

DESCRIPTION THE PREFERRED EMBODIMENT

In the 1 and 2 is initially a vehicle power transmission system generally with 11 designated. In the power train 11 is a representative form of a multiple mode (EVT) multi-mode, electrically variable compound transmission that is particularly suited to the implementation of the controls of the invention and incorporated herein by reference 1 and 2 generally with the reference numeral 10 is designated. As can be seen especially in these figures, the EVT has 10 an input element 12 that by its very nature is a motor 14 directly driven shaft can be or in which, as in 2 is shown between the output element of the motor 14 and the input element of the EVT 10 a transition torque damper 16 can be integrated. The transition torque damper 16 may include a torque transmitting device (not shown) that selectively engages the engine 14 with the EVT 10 of course, this torque-transmitting device is not used to change or control the mode of operation in which the EVT 10 is working.

In the embodiment shown, the engine 14 a fossil fuel engine such as a diesel engine that is easily adaptable to provide its available output delivered at a constant number of revolutions per minute (min ^-1 ). In the exemplary embodiment to which the 1 and 2 are directed, the engine can 14 in accordance with a desired operating point, which can be determined from the driver inputs and the driving conditions, - after starting and predominantly during the input - to operate at a constant speed or at a plurality of constant speeds.

The EVT 10 uses three partial planetary gears 24 . 26 and 28 , The first part planetary gearbox 24 has an outer gear member generally referred to as the ring gear 30 that is an inner gear member generally referred to as the sun gear 32 rewrites. Several planetary gear elements 34 are rotatable on a support 36 attached so that each planetary gear element 34 both with the outer gear element 30 as well as with the inner gear element 32 is engaged.

The second part planetary gearbox 26 also has an outer gear member generally referred to as the ring gear 38 , which is an inner gear member commonly referred to as a sun gear 40 rewrites. Several planetary gear elements 42 are rotatable on a support 44 attached so that each planetary gear element 42 both with the outer gear element 38 as well as with the inner gear element 40 is engaged.

The third part planetary gearbox 28 also has an outer gear member generally referred to as the ring gear 46 , which is an inner gear member commonly referred to as the sun gear 48 rewrites. Several planetary gear elements 50 are rotatable on a support 52 attached so that each planetary gear element 50 both with the outer gear element 46 as well as with the inner gear element 48 is engaged.

Although all three part planetary gearboxes 24 . 26 and 28 themselves are "simple" part planetary gear, are the first and the second part planetary gear 24 and 26 composed in that the inner gear member 32 of the first part planetary gear 24 as about a clutch hub wheel 54 with the outer gear member 38 of the second part planetary gear 26 connected is. The inner gear element 32 of the first part planetary gear 24 and the outer gear member 38 of the second part planetary gear 26 that are connected to each other are like a hollow shaft 58 rotatably with a first electric motor / generator 56 connected. Occasionally, the first electric motor / generator 56 also referred to as electric motor A or M _A.

As the carrier 36 of the first part planetary gear 24 like over a wave 60 with the carrier 44 of the second part planetary gear 26 connected are the partial planetary gears 24 and 26 further composed. Thus, the carriers 36 and 44 of the first part planetary gear 24 or the second part planetary gear 26 connected. Besides, the wave is 60 as about a torque transmitting device 62 which is used to select the modes of operation of the EVT, as explained more fully below 10 to assist, optionally with the carrier 52 of the third part planetary gear 28 connected. Occasionally, the torque transmitting device 62 here also referred to as second clutch, clutch two or C2.

The carrier 52 of the third part planetary gear 28 is directly with the transmission output element 64 connected. If the EVT 10 used in an agricultural vehicle, the output element 64 be connected to the (not shown) vehicle axles, which in turn terminate in the (also not shown) drive elements. The drive members may be either the front wheels or the rear wheels of the vehicle on which they are used, or may be the rear axle of a caterpillar.

The inner gear element 40 of the second part planetary gear 26 is like a hollow shaft 66 that the wave 60 circumscribes with the inner gear member 48 of the third part planetary gear 28 connected. The outer gear element 46 of the third part planetary gear 28 is via a torque transmitting device 70 optionally connected to the ground through the gear housing 68 is shown. As will be explained below, the torque transmission device 70 also used to help in choosing the modes of operation of the EVT 10 to help. Occasionally, the torque transmitting device 70 Also referred to here as the first clutch, clutch one or C1.

In addition, the hollow shaft 66 rotatably with a second electric motor / generator 72 connected. Occasionally, the second electric motor / generator 72 Here also be referred to as electric motor B or M _B. All partial planetary gearboxes 24 . 26 and 28 and the electric motor A and the electric motor B ( 56 . 72 ) are like the axially arranged shaft 60 coaxially oriented. It is noted that the two electric motors A and B have an annular configuration that allows them to be the three partial planetary gears 24 . 26 and 28 rewrite, so that they are arranged radially within the electric motors A and B. This configuration ensures that the overall envelope - ie the perimeter dimension - of the EVT 10 is minimized.

At the entrance element 12 can be a drive gear 80 be provided. As shown, the drive gear connects 80 the input element 12 firmly with the outer gear element 30 of the first part planetary gear 24 so that the drive gear 80 the power of the engine 14 and / or from the electric motor or the electric motors / from the generator or the generators 56 and or 72 receives. The drive gear 80 is with an impeller 82 engaged, in turn, with a transmission gear 84 engaged at one end of a shaft 86 is attached. The other end of the wave 86 can be connected to a transmission fluid pump 88 be attached to the fluid well 37 Transmission fluid is supplied, passing high-pressure fluid to the regulator 39 supplies a portion of the fluid to the fluid pan 37 returns and in the lead 41 generates a regulated line pressure.

In the described exemplary mechanical arrangement, the output element receives 64 via two different gear trains within the EVT 10 Power. A first mode or a first gear train is selected when the first clutch C1 is operated to the outer gear member 46 of the third part planetary gear 28 "to connect to the ground". A second mode or gear train is selected when the first clutch C1 is released and at the same time the second clutch C2 is actuated about the shaft 60 with the carrier 52 of the third part planetary gear 28 connect to. An operating mode with respect to a gear train is indicated here with capital letters such as OPERATING MODE 1 or OPERATING TYPE 2 or designated M1 or M2. The person skilled in the art recognizes that the MODE 1 is an input split mode while the MODE is 2 is a multi-share bonded mode.

It is clear to one skilled in the art that the EVT 10 in each mode of operation can provide a range from relatively slow to relatively fast output speeds. This combination of two modes with a slow to fast output speed range in each mode allows the EVT 10 driving a vehicle from a steady state to highway speeds. In addition, a fixed-gear condition is available in which the two clutches C1 and C2 are simultaneously engaged to efficiently mechanically couple the input member to the output member via a fixed gear ratio. In addition, a neutral state is available in which the two clutches C1 and C2 are simultaneously disengaged to mechanically decouple the output member from the transmission. Finally, the EVT 10 provide synchronized circuits between the modes in which the slip speed across the two clutches C1 and C2 is substantially zero. Further details regarding the operation of the exemplary EVT can be found in commonly assigned United States Patent No. 5,931,737, the contents of which are incorporated herein by reference.

The motor 14 is preferably a diesel engine which, as in 2 shown electronically by the engine control module (ECM) 23 is controlled. The ECM 23 is a conventional microprocessor-based diesel engine control unit which incorporates such common elements as a microprocessor, a read-only memory ROM, a random access memory RAM, an electrically programmable read-only memory EPROM, a fast clock, analog-to-digital (A / D) and digital-to-analog (D / A) circuitry, one input Output / output devices (I / O) and appropriate signal conditioning and buffer circuitry. The ECM 23 operates by collecting data from a plurality of sensors via a plurality of discrete lines or a plurality of actuators of the motor 14 controls. For the sake of simplicity, the ECM 23 generally with a bidirectional interface over the loop group 35 with the engine 14 shown. Among the various parameters provided by the ECM 23 can be scanned are the oil pan and engine coolant temperature, engine speed (Ne), turbo pressure and ambient air temperature, and ambient air pressure. Various actuators by the ECM 23 may include fuel injection pumps, fan controllers, engine heaters including glow plugs, and grate intake air preheaters. Preferably, in response to a torque command Te_cmd provided by the control system of the EVT, the ECM provides well-known torque-controlled controls for the engine 14 , These engine electronics, controls and sizes are well known to those skilled in the art, so their further detailed explanation is not required here.

As apparent from the above description, the EVT receives 10 optional power from the engine 14 , As further on from 2 In addition, the EVT receives power from an electrical storage device such as one or more batteries in the battery pack module (BPM). 21 , In addition, the powertrain system includes such energy storage devices that are an integral part of its power flows. Without changing the concepts of the invention, other electrical storage devices that store and dispense electrical power may be used instead of the batteries. The BPM 21 is a high voltage DC voltage that is supplied via DC power lines 27 with a two-power inverter module (DPIM) 19 is coupled. In accordance with whether the BPM 21 Charging or discharging can supply power to or from the BPM 21 be transmitted. The DPIM 19 includes a pair of power inverters and respective electric motor control units configured to receive motor control commands and control inverter states therefrom to generate electric motor drive or regenerative functionality. The electric motor control units are microprocessor-based control units including such common elements as a microprocessor, a read only memory ROM, a random access memory RAM, an electrically programmable read only memory EPROM, a fast clock generator, an analog / digital circuitry (A / D) and digital / analog circuitry (D / A) and input / output circuitry and input / output (I / O) devices and suitable signal conditioning and buffer circuitry. In the electric motor control, the respective inverters receive power from the DC lines and supply via the high voltage phase lines 29 and 31 AC to the respective electric motor. In recovery control, the respective inverter receives over the high voltage phase lines 29 and 31 AC power from the electric motor and supplies power to the DC power lines 27 , The total DC current supplied to or from the inverters determines the charging or discharging mode of the BPM 21 , Preferably, the M _A and the M _{B are} three-phase AC machines, the inverters including complementary three-phase power electronics. The individual electric motor speed signals Na and Nb for M _A and M _B are also by the DPIM 19 derived from the electric motor phase information or via conventional rotation sensors. These electric motors, electronics, controls and sizes are generally well known to those skilled in the art, so their further detailed explanation is not required here.

The system controller 43 is a microprocessor based control unit incorporating such common elements as a microprocessor, a read only memory ROM, a random access memory RAM, an electrically programmable read only memory EPROM, a fast clock generator, an analog / digital circuitry ( A / D) and digital / analog circuitry (D / A), a digital signal processor (DSP) and input / output circuitry, and input / output devices (I / O) and suitable signal conditioning and buffer circuitry. In the exemplary embodiment, the system controller includes 43 a pair of microprocessor-based control units acting as vehicle control module (VCM) 15 and as a transmission control module (TCM) 17 are constructed. The VCM and the TCM may e.g. B. a variety of control and diagnostic functions with respect to the EVT and on the vehicle chassis including z. B. engine torque commands, input speed control and output speed control along with regenerative braking, anti-lock braking and train control provide. In particular, the system controller operates 43 in terms of the functionality of the EVT, to directly sense data from a plurality of sensors over multiple discrete lines, or directly control a plurality of EVT actuators. For the sake of simplicity, the system controller 43 generally with a bidirectional interface over the loop group 33 shown with the EVT. In particular, will noted that the system control unit 43 Frequency signals from rotation sensors are received to use for controlling the EVT 10 to the speed Ni of the input element 12 and the speed No of the output element 64 to process. In addition, the system control unit 43 Receive and process pressure signals from pressure switches (not shown separately) to monitor the apply chamber pressures of clutches C1 and C2. Alternatively, pressure monitoring by means of pressure transducers can be used for a wide range. The system controller sends PWM control signals and / or binary control signals to the EVT 10 to control the filling and emptying of the clutches C1 and C2 so that they are engaged and disengaged. In addition, the system control unit 43 Temperature data of the transmission fluid sump 37 such as received from a conventional thermocouple input (not shown separately) to divert the fluid well temperature Ts and provide a PWM signal that can be derived from the input speed Ni and from the well temperature Ts, via the controller 39 to control the line pressure. The filling and emptying of the clutches C1 and C2 is effected by means of solenoid controlled spool valves responsive to the above-mentioned PWM control signals and binary control signals. In order to achieve a precise arrangement of the slide in the valve body and a correspondingly accurate control of the clutch pressure during engagement, it is preferable to use control valves which use variable-passage electromagnets. Similarly, the line pressure regulator 39 of an electromagnetically controlled variety to establish a regulated line pressure in accordance with the described PWM signal. These line pressure controls are well known to those skilled in the art. The clutch slip speeds via the clutches C1 and C2 are derived from the output speed No, from the M _A speed Na and from the M _B speed Nb; more specifically, the slip of C1 is a function of No and Nb, while the slip of C2 is a function of No, Na and Nb. Also, a user interface block (UI block) 13 shown such inputs to the system controller 43 such as the vehicle throttle position, the push-button automatic selector switch (PBSS) for selecting the available range of drive, the braking force and fast idle requirements, among others.

The system controller 43 determines a torque command Te_cmd and delivers it to the ECM 23 , The torque command Te_cmd represents the torque contribution of the EVT desired by the engine as determined by the system controller. In addition, the system controller determines 43 a speed command Ne_des representing the desired input speed of the EVT, which is also the desired engine speed operating point in the direct coupled arrangement between the engine and the EVT. In the direct coupled arrangement exemplified here, the engine torque and the input torque of the EVT, Te and Ti, respectively, are equivalent, and may be referred to alternatively herein. Similarly, the engine speed and input speed of the EVT, Ne and Ni, respectively, are equivalent, and may be referred to here alternatively. The desired operating points of the input torque are preferably determined as disclosed in commonly assigned and co-pending United States Serial No. 10 / 799,531 (Attorney Docket No. GP-304338), incorporated herein by reference. The desired operating speeds of the input speed are preferably determined as described in commonly assigned and co-pending United States Application Serial Nos. 10 / 686,508 (attorney docket GP-304193) and 10 / 686,034 (attorney docket GP-304194). which is incorporated herein by reference. A preferred speed control for a hybrid transmission is described in detail in commonly assigned and co-pending United States Application Serial No. 10 / 686,511 (Attorney Docket No. GP-304140) incorporated herein by reference.

The various described modules (ie the system controller 43 , the DPIM 19 , the BPM 21 , the ECM 23 ) communicate via a Controller Area Network bus (CAN bus) 25 , The CAN bus 25 allows the transmission of control parameters and commands between the different modules. The specific communication protocol used is application-specific. For example, the preferred protocol for high performance applications is the Society of Automotive Engineers J1939 standard. The CAN bus and the appropriate protocols provide robust messaging and multi-controller interface between the system controller, the ECM, the DPIM, the BPIM, and other control units such as the anti-lock brake and the train control units.

In 3 is for the EVT 10 FIG. 4 illustrates a graph of the output speed No on the horizontal axis versus the input speed Ni on the vertical axis. FIG. Through the line 91 the synchronous operation is shown, that is, those relationships between input speed and output speed at which the two clutches C1 and C2 simultaneously operate at substantially the slip speed zero above them. Thus, it represents those relationships between input and output speeds at which substantially synchronous switching can take place between modes, or at de NEN by simultaneous engagement of both clutches C1 and C2, also known as fixed translation, a direct mechanical coupling from the input to the output can be effected. A special gearbox relationship, the by the straight line 91 in 3 shown synchronous operation is as follows: The outer gear member 30 has 91 teeth, the inner gear element 32 has 49 teeth, the planetary gear elements 34 own 21 teeth; the outer gear member 38 has 91 teeth, the inner gear element 40 has 49 teeth, the planetary gear elements 42 own 21 teeth; the outer gear member 46 has 89 teeth, the inner gear element 48 has 31 teeth, the planetary gear elements 50 have 29 teeth. Occasionally, the straight line 91 also referred to here as a synchronous straight line, transformation ratio straight line or fixed translation straight line.

Left of the gear ratio straight 91 is a preferred operating area 93 for the first mode, in which C1 is engaged and C2 is disengaged. Right of the transformation ratio line 91 is a preferred operating area 95 for the second mode, in which C1 is disengaged and C2 is engaged. The term indented herein indicates a substantial torque transfer capability across the respective clutch with respect to the clutches C1 and C2, while the term disengaged indicates an insubstantial torque transfer capability across the respective clutch. Since it is generally preferred to cause circuits to transition synchronously from one mode to another, torque transmissions are caused to occur from one mode to another via a two-clutch engagement fixed ratio during a finite period of time prior to disengagement of the currently engaged clutch the currently disengaged clutch is engaged. In addition, the mode change is completed when, by constantly engaging the clutch associated with the operating mode that is entered, and disengaging the clutch associated with the operating mode being exited, the fixed gear has been left.

Although the operating area 93 for the operation of the EVT in the OPERATING MODE 1 is generally preferred, this does not mean that the operation in the OPERATING 2 the EVT can not take place or does not take place. Because the OPERATING TYPE 1 Preferably, gearboxes and motor systems used for the high starting torques in the area 93 are particularly well suited in various respects (eg, mass, size, cost, inertia, etc.) but are generally preferred in the field 93 in the OPERATING TYPE 1 to work. Although the operating area 95 for the operation of the EVT in the OPERATING MODE 2 is generally preferred, this is not to say that the operation in the OPERATING MODE 1 the EVT can not take place or does not take place. Because the OPERATING TYPE 2 Preferably, gearboxes and engine systems are used in various respects (eg, mass, size, cost, inertia, etc.) for the high speeds of the range 95 are particularly well suited, but are generally preferred in the field 95 in the OPERATING TYPE 2 to work.

The area 93 , in which the operation in the OPERATING MODE 1 is generally preferred, may be considered as a region of slow speeds while the region 95 , in which the operation in the OPERATING MODE 2 is generally preferred, can be considered as high speed area. Switching to the OPERATING MODE 1 is regarded as a downshift, with a higher gear ratio associated with it in accordance with the relationship of Ni / No. It also switches to the OPERATING MODE 2 is considered to be upshifting, being assigned a lower gear ratio in accordance with the relationship of Ni / No.

Now on the basis of 4A shows an exemplary electric motor torque subspace (Ta-Tb space) for operation in the OPERATION MODE 2 given values of Na and Nb, the torque of the electric motor A (M _A ) plotted on the horizontal axis and the torque of the electric motor B (M _B ) plotted on the vertical axis. Limits are drawn that correspond to a particular exemplary maximum torque and minimum torque of the electric motor A (Ta_min, Ta_max), with the maximum and minimum related to the engine capabilities at certain exemplary present operating conditions being Na (ie, Ni, No, and Mode) whose exact values for the present representation of 4 and are not required for the following discussion. Similar limits are shown corresponding to such exemplary maximum and minimum torque of the electric motor B (Tb_min, Tb_max), where the maximum and minimum with respect to the motor capabilities in certain exemplary present operating conditions are Nb (ie, Ni, No and mode). taken. The space bounded by the maximum and minimum electric motor torques represents a permissible solution space for the electric motor units M _A and M _B under present conditions. This is a general representation of allowable electric motor torque dissipation space for a two-motor EVT power transmission system such as the power transmission system 11 it being understood, however, that the general concepts described herein for a two-electric motor system will be appreciated by those of ordinary skill in the art transmission systems may be extended to include more than two electric machines that are operatively and optionally coupled to the transmission as described herein in order to define a corresponding multi-dimensional solution space of allowable electric motor torques.

Within This electric motor torque space are various other parameter lines constant values for a given value of Ni dot and No_dot drawn. There are Plotted several lines of constant battery power Pbat, the within the electric motor torque space solutions represent constant battery power. Furthermore are within this electric motor torque space lines constant Output torque To which solutions are constant within the room Represent output torque. After all are within the electric motor torque space lines constant Input torque drawn therein, the solutions in constant input torque represent. Increasing and decreasing trend directions for these respective constancy lines are shown by respective two-sided arrows representing the respective Zero Konstanz lines assigned.

Although the trend and tilt relationships between the torque lines (To, Ti, Ta, and Tb) remain the same for other system operating conditions in Ni, No, Ni_dot, and No_dot as described in US Pat 4A are shown, it is noted here that the lines of constant battery power can change significantly from the example shown in the figure.

In fact, the lines of constant battery power are segments of closed, substantially elliptic constant battery power. Realizable operating conditions in Ni, No, Ni_dot, and No_dot may include cuts with lines of constant battery power in the Ta-Tb space that correspond to those in the 4A illustrated trend relationship of battery power z. B. substantially offset. In fact, the Ta-Tb space may be substantially in any orientation relative to the focal points of the battery power ellipses, resulting in substantially any orientation and trend of constant battery power lines intersecting the Ta-Tb space. In addition, the Ta-Tb space may be closer to the focal points of the battery power ellipses, resulting in a greater curvature of the lines of constant battery power intersecting the Ta-Tb space and potentially increasing their intersections with the Ta-Tb limits ,

Although the subspace in terms of the determined minima and maxima of Ta and Tb (Ta_min, Ta_max, Tb_min, Tb_max) in the graph 4A is permissible in accordance with the torque capabilities of the respective electric motor units, the constant battery power (Pbat) lines, constant output torque (To) lines, and constant input torque (Ti) lines do not necessarily represent allowable solutions with respect to the capabilities of their respective subsystem at the respective ones Conditions, but a theoretically unlimited modeling of the system within the electric motor torque space.

As indicated, represents 4A a torque chamber suitable for operation in the OPERATING MODE 2 suitable is. A similar torque space in 4B of course, there is for the OPERATING TYPE 1 , However, shows 4B for clarity green no lines of constant battery power. It is important to note that the lines have constant input torque in 4B appear vertically as the input torque in the input split configuration of the OPERATION MODE 1 is decoupled from the torque of the electric motor B. It is also noted that the input torque Ti in the figure increases from right to left, and the output torque To increases from the lower right to the upper left.

The specific case of the OPERATING TYPE 2 Emphasizes the general rule that the electric motor torque range described and illustrated here to all EVT configurations and modes, by the numerous possible coupling combinations between electric motors, motors and outputs of an electrically variable transmission including modes, the inputs and outputs completely from decouple from one or more electric motor torques, be set, is customizable. Thus, in the exemplary illustration of the present invention, there will be no separate detailed discussion of the MODE 1 performed. However, in the entire description of the OPERATING TYPE 2 on notable differences or distinctions that affect the OPERATING TYPE 1 applicable. However, the more general case of operation is in the OPERATING MODE 2 in that the input is torque-coupled to both electric motors A and B, it will of course be sufficient for those skilled in the art to understand their application to more specific cases including complete torque decoupling of one or more electric motors from the input of the EVT.

Within this motor torque space, it is desirable to determine an available maximum or available peak or allowable output torque. Such peak output torque is or is defined by various thresholds of the system, subsystem, and components. Based on the schedule 6 and the more detailed Ta-Tb-space diagrams of the 7 - 10 In the following, a preferred method for determining the maximum available output torque within an allowable solution space in accordance with the motor and motor torque limits will be set forth. The flowchart illustrates representative steps for carrying out the method of the present invention that includes instructions that are included as part of the executable computer code and data structures of the system controller 43 are realized. Of course, the commands presented here are executed as part of a much larger set of instruction sets and routines that perform the various control and diagnostic functions of the powertrain previously described.

wobei Ta das Drehmoment des Elektromotors A;
Tb das Drehmoment des Elektromotors B;
Ti das Eingangsdrehmoment des EVT;
To das Ausgangsdrehmoment des EVT;
Ni_dot die Eingangsdrehbeschleunigung des EVT;
No_dot die Ausgangsdrehbeschleunigung des EVT; und
[K₁] eine 2 × 4-Matrix von Parameterwerten, die durch die Zahnradanlage und durch die Wellenzwischenverbindungen und durch geschätzte Anlagenträgheiten, die auf den momentanen Antriebsbereich anwendbar sind, bestimmt sind, ist.A model of the EVT is provided that includes stationary and dynamic EVT system parameters. In its basic form - which is suitable for resolution after engine torque - the model is represented as follows:

where Ta is the torque of the electric motor A;
Tb is the torque of the electric motor B;
Ti is the input torque of the EVT;
To the output torque of the EVT;
Ni_dot the input spin of the EVT;
No_dot the output spin of the EVT; and
[K ₁ ] is a 2 × 4 matrix of parameter values determined by the gear system and by the shaft interconnections and by estimated system inertias applicable to the current drive range.

wobei im Unterschied zu dem wie oben in Gleichung (1) dargestellten Modell
Ucl ein gemessener Drehmomentfehlerterm, der auf dynamischen Bedingungen beruht, z. B. ein Eingangsdrehzahlfehler, ist; und
[K₂] eine 2 × 5-Matrix von Parameterwerten ist, die ferner Parameter enthält, um den gemessenen Drehmomentfehlerterm Ucl zu skalieren, um die Elektromotordrehmomente Ta und Tb zu ändern.Preferably, an additional torque error term is introduced into the model which provides the preferred form shown as follows:

unlike the model shown in equation (1) above
Ucl is a measured torque error term based on dynamic conditions, e.g. An input speed error; and
[K ₂ ] is a 2 × 5 matrix of parameter values, which further includes parameters to scale the measured torque error term Ucl to change the motor torque Ta and Tb.

additional Details regarding the measured torque error term and preferred methods for its determination are described in commonly assigned and simultaneously pending Application of the United States Serial No. 10 / 686,511 (file reference Attorney GP-304140).

wobei Na die Drehzahl des Elektromotors A,
Nb die Drehzahl des Elektromotors B,
Ni die Eingangsdrehzahl des EVT,
No die Ausgangsdrehzahl des EVT und
[K₃] eine 2 × 2-Matrix von durch die Zahnradanlage und durch die Wellenzwischenverbindungen bestimmten Parameterwerten ist.Various parameters of the powertrain model are measured or otherwise determined. The output speed No and the input speed Ni are preferably derived from sampled and filtered electric motor speeds Na and Nb known by sampling are derived via the electric motor control phase information. The input speed Ni and the output speed No may be derived from the electric motor speeds in accordance with the following known coupling constraint equation:

where Na is the rotational speed of the electric motor A,
Nb is the rotational speed of the electric motor B,
Ni is the input speed of the EVT,
No the output speed of the EVT and
[K ₃ ] is a 2 × 2 matrix of parameter values determined by the gear system and by the shaft interconnections.

The Output spin No_dot is preferably in accordance determined at the derived output speed No, while the Input spin acceleration Ni_dot preferably a desired rate of change the input speed is that at the derived input speed Ni and on a profile / rate limit control, as shown in the transmitted jointly and simultaneously pending Application of the United States Serial No. 10 / 686,511 (file reference Attorney GP-304140).

Now on the basis of the schedule 6 starts in the block 170 a set of exemplary steps for carrying out the present invention determining the appropriate model to use in accordance with the currently active mode of operation of the EVT. As noted above, the basic form of the model remains the same from one mode to the next, while the matrix of parameter values may be different in accordance with the transmission system and the shaft interconnections and the estimated system inertia applicable to the drive range of interest. Below are in the block 172 determines the engine torque limits. Since at this point it is an object to determine EVT operation at various system limits or constraints, the engine torque limits for Ta and Tb provide the values used to calculate the input torque Ti in accordance with these engine torque limits. The engine torque limits refer to individual maximum and minimum motor torque, and more particularly to pairs of such complementary maximum and minimum motor torque.

The limits or limitations on the motor torque are reflected in 5 in which the maximum and minimum electric motor torques (Ta_min, Ta_max, Tb_min and Tb_max) within the capabilities of the electric motor under the present conditions are preferably obtained from data sets stored in tabular form in data structures in the system controller 43 are stored. These datasets are provided for reference by the pre-stored table format routine and have been empirically derived from conventional dynamometer tests of combined electric motor and power electronics (eg, power inverters) at various temperature and voltage conditions. An exemplary representation of such characteristic electric motor torque-speed data is shown in FIG 5 Figure 4 illustrates in which the maximum and minimum data for a given speed through the line of constant speeds 112 are representative, the exemplary lines of constant temperature / voltage 111 . 113 cuts. The tabulated data is referenced by the motor speed (Na, Nb), by the voltage and by the temperature.

Although the electric motors are used in both the electric motor and generator modes - suggesting four quadrants (I, II, III, IV) of the torque / speed data - is a two-quadrant data collection in which the adjacent quadrants collected data is only mirrored into other quadrants and not directly measured, generally sufficient. In the present example, the quadrants I and II are the specific data 111 shown while the quadrants III and IV with the data mirrored from it 113 are shown occupied.

Preferably, the maximum and minimum motor torque (Ta_min, Ta_max, Tb_min and Tb_max) derived from the data structures are further set to ensure reservation of a predetermined amount of torque capacity at the limits. This reservation results in a Ta-Tb space for use in the EVT control, which is more conservative in terms of the actual allowable Ta-Tb space. Various dynamic considerations including considerations such as electric motor spins and arithmetic and execution loop delays It is desirable to have such reservations inherent in any computerized controller implementation. A preferred manner of determining such torque reservations is disclosed in copending and commonly assigned United States Application Serial No. 10 / 846,153 (Attorney Docket No. GP-305160), the contents of which are incorporated herein by reference.

7 Figure 14 shows the allowable Ta-Tb torque space as the central, unshaded portion within the various maximum and minimum limits of Ta and Tb.

wobei [K₄] eine 2 × 2-Matrix ist, die die wie in der obigen Gleichung (2) dargelegten umgeordneten Parameterwerte umfasst.Subsequently, the block is calculated 174 the maximum and minimum input torques (Ti_mach_max and Ti_mach_min) corresponding to the maximum and minimum engine torque pairs. The block 174 requires a manipulation of the model to reorder for resolution from known or assumed parameters according to the desired parameters, in this case the input torque, and takes the following form:

where [K ₄ ] is a 2 × 2 matrix comprising the rearranged parameter values as set forth in Equation (2) above.

From the above equation (4), by directly inputting their values into the model, the input torques corresponding to the engine torques Ta and Tb can be calculated. With additional reference to the Ta-Tb space in 7 starting at the top right and going clockwise around the figure to the intersections of the T and Tb limits, the pairs of engine torque limits correspond to: Ta_max, Tb_max; Ta_max, Tb_min; Ta_min, Tb_min; and Ta_min, Tb_max. In the model, individual replacements of these four pairs of engine torque limits could be made to return corresponding input torques. From the characterizations of the Ta-Tb system space (see 4A However, it is known that a maximum input torque at the engine limit values corresponds to the pair Ta_max, Tb_min and a minimum input torque at the engine limit values corresponds to the pair Ta_min, Tb_max. As based on 4B can be checked is the orientation of the minimum and maximum output torques for the OPERATING TYPE 1 of course opposite. These pairs are distinguished in the figure by circles at the respective engine torque threshold pairs. Thus, the maximum input torque corresponding to the engine torque limits is represented by the line of constant input torque indicated by (Ti_mach_max), which is shown as the engine torque limit pair Ta_max, Tb_min in its rightmost lower intersection in FIG cuts. Similarly, the minimum input torque corresponding to the engine torque limits is thus represented by the constant input torque line denoted by (Ti_mach_min), which is shown as the engine torque limit pair Ta_min, Tb_max in its leftmost upper intersection in FIG Figure cuts.

In operation in the OPERATING MODE 1 in which the motor does not further restrict the Ta-Tb space, Ti_mach_max and Ti_mach_min directly correspond to Ta_min and Ta_max, respectively. That is, in the Ta-Tb torque space, Ti_mach_max is above Ta_min and Ti_mach_min above Ta_max. In addition, if the engine torque is in the OPERATING MODE 1 more restrictive than the engine torque, the Ta_min or Ta_max is substantially substituted by the restricted engine torque maximum or minimum.

Subsequently, the block determines 176 the maximum and minimum input torques as a function of available peak motor torque (Ti_eng_max, Ti_eng_min). As previously described, the motor and input of the EVT are directly coupled. Thus, there is a direct correspondence between the engine torque and the input torque. Engine torque is determined relative to a preset set of engine operating parameters, preferably engine speed and intake air pressure (air pressure or boost pressure, depending on normal intake or turbo-intake). Preferably, the obtain available peak engine torque from data sets stored in tabular form in data structures in the system controller 43 are stored. These records are provided for reference by the pre-stored table format routine, being empirically derived from conventional dynamometer tests, or as provided in engine manufacturer specification data. In determining the available peak engine torque, other factors such as air density, fuel type (for propulsion), engine retarder activation (for braking), and controlled limits (eg, fault-responsive engine output limiters) may be considered. Alternatively, the ECM 23 Provide peak motor performance data, such as in accordance with the Society of Automotive Engineers standard J1939, for use in determining the available motor torque peak maximum data and minimum data for use in the present control substantially in real time.

In the block 178 For example, the most limited input torques are selected from the respective maximum and minimum engine and engine torques (Ti_mach_max, Ti_mach_min, Ti_eng_max, Ti_eng_min) as the maximum and minimum input torques Ti_max and Ti_min. In 7 For example, an exemplary maximum input torque is referred to as a function of the engine torque limit as Ti_eng_max. In this example in 7 For example, Ti_eng_max as a function of the engine torque limits Ti_mach_max is less restrictive than the maximum input torque, ie, not less than Ti_mach_max. In 8th For example, an exemplary maximum input torque is referred to as a function of the engine torque limit as Ti_eng_max. This input torque derived from the motor torque limit is more restrictive than the maximum and minimum input torques in this example as functions of the engine torque limits Ti_mach_max and Ti_mach_min. The remaining allowable torque space - which is now further limited by the allowable maximum input torque determined as a function of engine torque limits - is off through the now contracted central unshaded portion 8th shown. In the present example 8th For example, it is assumed that no further restrictions on the Ta-Tb space with respect to the minimum torques are provided by the motor. Of course, these restrictions could of course be drawn in a similar way.

Below are in the block 180 and additionally based on 9 Evaluations performed only in operation in the OPERATING MODE 2 are required since in operation in the OPERATING MODE 1 any engine torque limitations to the Ta-Tb space as previously mentioned by substituting the more restrictive input torque for the appropriate among Ta_max and Ta_min are considered. In the block 180 Ti_max and Ti_min are evaluated with respect to the input torques calculated according to the engine torque threshold pairs at the four intersections of Ta_max, Ta_min, Tb_max and Tb_min. From the characterizations of the Ta-Tb system space (see 4A ), it is known that only the two sets of mutually adjacent pairs of engine torque limits corresponding to Ta_max and Tb_max need to be evaluated against Ti_max. In addition, it is also known that only the two sets of mutually adjacent pairs of engine torque limits corresponding to Ta_min and Tb_min need to be evaluated against Ti_min. Adjacent sets of engine torque threshold pairs are provided to the model to determine operating values for the input torques. For example, Ta_max and Tb_min are supplied to the model to calculate a first value (Ti_temp1) for the input torque. Similarly, the adjacent set of engine torque limits Ta_max and Tb_max is provided to the model to calculate a second value (Ti_temp2) for the input torque. Thereafter, Ti_max is evaluated against the two engine limit torque values Ti_temp1 and Ti_temp2 to determine if Ti_max intersects Ta_max. In the present example of Ti_max, it can be seen that Ti_max is between the machine limited torque values Ti_temp1 and Ti_temp2 as shown by the intersection of Ti_max with Ta_max. This result determines that the electric motor A - which corresponds to the machine-limited maximum torque Ta_max - is the restricting machine with respect to the generation of the least restricted output torque at maximum input torque Ti_max. If, as by the intersection of with 101 Instead, Ti_max is randomly located between the mutually adjacent machine-limited torque threshold pairs corresponding to Tb_max, ie (Ta_max, Tb_max) and (Ta_min, Tb_max), this result instead determines that the electric motor B - which corresponds to the Tb_max machine limited maximum torque Tb_max - the limiting machine with respect to the generation of the least limited output torque at maximum input torque Ti_max. Although this evaluation process has been described with respect to Ti_max, the same procedure, calculations, and determinations are made with respect to Ti_min and machine limited output torque generation. However, the evaluation in terms of determining the restricting machine in terms of the least limited output torque generation at minimum input torque Ti_min with respect to the two mutually adjacent sets of engine torque threshold pairs corresponding to Ta_min and Tb_min.

wobei im Unterschied zu dem Modell, wie es oben in den ähnlichen Modellgleichungen dargestellt ist,
[K₅] eine 2 × 5-Matrix ist, die die umgeordneten Parameterwerte des wie oben dargelegten Modells umfasst;
Ti gleich Ti_max oder Ti_min ist, wie es in Übereinstimmung mit den Maschinen- oder Motordrehmoment-Grenzwerten und ferner in Übereinstimmung mit dem zu bestimmenden gewünschten Ausgangsdrehmoment-Grenzwert (z. B. To_max_TaTbTi bzw. To_min_TaTbTi) berechnet oder bestimmt wurde; und
Ta in Übereinstimmung mit dem gewünschten zu bestimmenden Ausgangsdrehmoment-Grenzwert (z. B. To_max_TaTbTi bzw. To_min_TaTbTi) gleich Ta_max oder Ta_min ist.After the model has calculated the maximum and minimum input torques in accordance with the engine limit values or determined in accordance with the engine torque limits, and the respective constrained machines corresponding to the least constrained maximum and minimum output torques for the maximum and minimum input torques the minimum input torque has been determined, the block uses 182 Now, re-model the model for calculating the maximum and minimum output torque for the EVT in accordance with the torque restriction parameters. The manipulation of the model for rearranging for the resolution according to the desired parameters, in this case the output torque, from the calculated or determined parameter limitations or constraints once again leads to the following present form in which the machine A is the particular constraining machine:

unlike the model, as shown above in the similar model equations,
[K ₅ ] is a 2 × 5 matrix comprising the rearranged parameter values of the model set forth above;
Ti is equal to Ti_max or Ti_min as calculated or determined in accordance with the engine or engine torque limits and also in accordance with the desired output torque limit (eg, To_max_TaTbTi and To_min_TaTbTi, respectively) to be determined; and
Ta is equal to Ta_max or Ta_min in accordance with the desired output torque limit to be determined (e.g., To_max_TaTbTi and To_min_TaTbTi, respectively).

wobei im Unterschied zu dem wie oben in den ähnlichen Modellgleichungen dargestellten Modell
[K6] eine 2 × 5-Matrix ist, die die umgeordneten Parameterwerte des wie oben dargelegten Modells umfasst;
Ti gleich Ti_max oder Ti_min ist, wie es in Übereinstimmung mit den Maschinen- oder Motordrehmoment-Grenzwerten und ferner in Übereinstimmung mit dem zu bestimmenden gewünschten Ausgangsdrehmoment-Grenzwert (z. B. To_max_TaTbTi bzw. To_min_TaTbTi) berechnet oder bestimmt wurde; und
Tb in Übereinstimmung mit dem gewünschten zu bestimmenden Ausgangsdrehmoment-Grenzwert (z. B. To_max_TaTbTi bzw. To_min_TaTbTi) gleich Tb_max oder Tb_min ist.Similar manipulation or rearrangement of the model where the machine B is the particular constraining machine is done as follows:

unlike the model illustrated above in the similar model equations
[K6] is a 2x5 matrix comprising the rearranged parameter values of the model set forth above;
Ti is equal to Ti_max or Ti_min as calculated or determined in accordance with the engine or engine torque limits and also in accordance with the desired output torque limit (eg, To_max_TaTbTi and To_min_TaTbTi, respectively) to be determined; and
Tb is equal to Tb_max or Tb_min in accordance with the desired output torque limit to be determined (e.g., To_max_TaTbTi and To_min_TaTbTi, respectively).

10 now illustrates the To_max_TaTbTi determined in relation to the above description. It is noted that in the OPERATING TYPE 1 the relationship (6) is used to calculate To_max_TaTbTi.

Those skilled in the art will appreciate from the foregoing description and in reminiscence of the Ta-Tb space of the various 7 - 10 clearly that the operation in the OPERATING 1 for the present torque restriction parameters at the point Ta_min, Tb_max always a maximum output returns torque and always returns a minimum output torque for the present torque constraint parameters at the point Ta_max, Tb_min. This is in the OPERATING MODE 1 regardless of whether the motor torque limits the Ta-Tb space or not, as long as the substitution discussed for the correct Ta limit, Ta_max or Ta_min, reflects the limiting engine torques. Further, it is clear that in operation in MODE 2, the maximum and minimum output torques are assigned to the point Ta_max, Tb_min and a minimum output torque is assigned at the point Ta_min, Tb_max if the motor does not restrict the Ta-Tb space.

Previously, when determining the maximum and minimum output torques, only torque parameters related to the machines and the engine were considered. In the following, another description will be given regarding battery performance parameters in determining the maximum and minimum output torques. It is based on the schedules of 12 and 13 and on the more detailed Ta-Tb-space diagrams of the 14 - 19 directed. The flowcharts illustrate representative steps for carrying out the method of the present invention, including instructions embodied as part of the computer system executable code and data structures 43 are implemented. Of course, the instructions thus represented are executed as part of a much larger set of instruction sets and routines that perform the various control and diagnostic functions of the previously described powertrain.

Based on 12 A number of processes for determining output torque limits taking into account battery power limitations and engine torque limitations are illustrated. Especially with regard to the block 212 For example, limits or limitations on the battery power Pbat min and Pbat max within the capabilities of the present conditions of the batteries are preferably determined from data sets stored in tabular form in data structures in the system controller 43 are stored. These records are provided for reference by the pre-stored table format routine and are available with different conditions, e.g. B. the state of charge, the temperature, the voltage and the use (amp hours / hour), has been correlated. A preferred method of determining minimum and maximum battery power is disclosed in commonly assigned and co-pending United States application.

No. 10 / 686,180 (attorney docket GP-304119), which is hereby incorporated by reference. The data referenced by the table may also be adjusted in accordance with an offset (Pbat limit offset), e.g. As further described below, and substantially in accordance with the following relationship: Pbat_max = Pbat_max_lu + Pbat_limit_offset; and (7) Pbat_min = Pbat_min_lu + Pbat_limit_offset (8) is determined by a filtered difference between estimated battery power and measured battery power.

In this case, Pbat_max_lu and Pbat_min_lu are referenced by the table
Values for the maximum or minimum battery power; and is
Pbat_lim_offset a filtered difference between estimated battery power and measured battery power, as further described below in accordance with relationship (12).

According to block 214 out 12 will be in accordance with the following relationship: Pbat_est = Pmotor_A + Ploss_A + Pmotor_B + Ploss_B (9) Battery power estimates (Pbat_est) delivered,
where Pmotor_A and Pmotor_B are the electric motor power of the unit A and the unit B, respectively; and
Ploss_A and Ploss_B are the combined electric motor and power electronics losses (electric motor losses) of unit A and unit B, respectively.

Pmotor_A and Pmotor_B are further resolved in accordance with the torque-speed relationship of the electric motors as follows: Pmotor_A = Ta ∙ Na; and (10) Pmotor_B = Tb ∙ Nb; (11) where Ta is the torque of the electric motor A;
Tb is the torque of the electric motor B;
Na the speed of the electric motor A; and
Nb is the rotational speed of the electric motor B.

Preferably, Ploss_A and Ploss_B are obtained from data sets stored in tabular form in data structures in the system controller 43 are stored. These records are provided for reference by the pre-stored table format routine, with the power losses correlated to and referenced by the motor torque and motor speed. The power losses are z. B. derived empirically from conventional dynamometer tests of common electric motor and power electronics (eg., Power inverter). In the 11A and 11B Torque-speed power loss characteristics are shown for typical rotary electric machines. In 11A are the lines of constant power loss 301 shown drawn in the torque-speed plane for the electric motor. With 303 designated broken line corresponds to a plane of constant electric motor speed and illustrated as in relation to 11B The general parabolic characteristics of the power loss as a function of the electric motor torque can be seen.

The difference between the estimated battery power Pbat_est and the measured electric power input after filtering provides the aforementioned offset as follows: Pbat_limit_offset = Filter (Pbat_est - Pbat_meas) (12) where Pbat_meas is determined in accordance with the following relationship: Pbat_meas = I ∙ V (13) where I is the current supplied to the electric motors; and
V is the voltage at which the power is supplied.

In accordance with block 214 out 12 For example, in conjunction with relationships (9) through (11) above, multiple engine torque key combinations or pairs (Ta, Tb) are used to estimate battery performance in these combinations. For the combinations known torque maxima, minima and -nullwerte, ie

Ta = Ta_max, Ta = 0, Ta = Ta_min, Tb = Tb_max, Tb = 0 and Tb = Tb_min, selected. These key combinations are in 14 clearly illustrated, wherein they are referred to differently at the outer limits of the allowable Ta-Tb torque space as P1-P8. Thus, the estimated battery power corresponding to the key combinations P1-P8 is estimated by the relationship (9) set forth above, when both the electric motor speeds and both the motor torques are known.

In the block 216 The battery power is determined as described above 6 are associated with the maximum and minimum output torques To_max_TaTbTi and To_min_TaTbTi for the maximum and minimum engine torque pairs. The blocks 218 and 230 build only the iterative execution of the block just described 220 on. The justification 220 is executed once for each of the maximum and minimum battery power limits (Pbat_limit), Pbat_max and Pbat_min.

The block 222 performs an evaluation on the maximum and minimum battery power Pbat_max and Pbat_min and on the estimated battery power associated with each of the key combinations P1-P8. Adjacent estimated battery powers at P1-P8 are e.g. B. is systematically compared to Pbat_max and Pbat_min as follows with respect to the key combinations. P1 <Pbat_max <P2 P1 <Pbat_min <P2 P2 <Pbat_max <P3 P2 <Pbat_min <P3 P3 <Pbat_max <P4 P3 <Pbat_min <P4 P4 <Pbat_max <P5 P4 <Pbat_min <P5 P5 <Pbat_max <P6 P5 <Pbat_min <P6 P6 <Pbat_max <P7 P6 <Pbat_min <P7 P7 <Pbat_max <P8 P7 <Pbat min <P8 P8 <Pbat_max <P1 P8 <Pbat_min <P1

Where Pbat_max or Pbat_min intersect the engine torque limits between the battery power associated with the key combinations, it is assumed that the respective battery power limit (Pbat_max or Pbat_min) exceeds the allowable system torque space in Ta-Tb as represented by the engine torque limits Ta_max, Ta_min, Tb_max and Tb_min is set, further restricts. It is also in 14 to see that Pbat_max (Δ) intersects Tb_max between P1 and P2 and Tb_min between P6 and P7. Similarly, it can be seen that Pbat_min (Δ) intersects Ta_min between P3 and P4 and Tb_min between P5 and P6.

Below are in the block 224 determines engine torque pairs corresponding to the intersections (Δ) at the respective maximum and minimum limits of Ta and Tb by the battery power estimation relationship (9) immediately repeated below. Pbat_est = Pmotor_A + Ploss_A + Pmotor_B + Ploss_B (9)

Recalling the essentially parabolic characteristic of the battery power losses, as described in the 11A and 11B 4, a generally quadratic formula provides a satisfactory correspondence of the battery power loss data to the motor torque and the motor speed. The general forms of quadratic loss relationships for the loss of each electric motor A and B are as follows: Ploss_A = Xa n ∙ Ta 2 + Ya n ∙ Ta + Za n (14) Ploss_B = Xb n ∙ Tb 2 + Yb n ∙ Tb + Zb n (15) wherein Xa _n , Ya _n and Za _{n are} empirically determined coefficients corresponding to the electric motor A at a plurality of predetermined motor speed control points n; and
Xb _n , Yb _n and Zb _{n are} empirically determined coefficients corresponding to the electric motor B at plural predetermined electric motor speed control points n.

It has been found that between the given electric motor speed control points n, a simple linear interpolation between adjacent speed control points (eg, n and n-1) for motor speeds returns coefficients satisfying correspondence of the battery power loss data to the intermediate motor speed, e.g. N <N <n-1. Substituting the above-described quadratic loss relationships (14) and (15) and substituting the known torque-speed relationships (10) and (11) set forth above into the battery power estimating relationship (9) provides the following relationship: Pbat_est = Ta ∙ Na + Xa n ∙ Ta 2 + Ya n ∙ Ta + Za n + Tb ∙ Nb + Xb n ∙ Tb 2 + Yb n ∙ Tb + Zb n (16)

The relationship ( 16 ) is then used in determining the engine torque pairs Ta and Tb at the points of intersection (Δ) with the respective maximum and minimum limits of Ta and Tb. It can be observed that both electric motor speeds Na and Nb are known and that one of the torques Ta and Tb, z. B. as one of Ta_max, Ta_min, Tb_max and Tb_min, wherein the relationship (16) is solved to provide the unknown one of the torques Ta and Tb. In 15 the unknown engine torque maximum battery power Pbat_max correspond to the torque of the electric motor A, passing through 411 and 413 designated vertical dotted lines are drawn.

With the machine torque pairs thus determined, the block calculates 226 below the corresponding output torques. In the calculation, the EVT model is called again. The arrangement of the model is here as in relationship (4), which in the following expediently still is repeated once.

Again in addition by means of 15 For example, in the preceding example, after the entire iteration has been performed, the four calculated output torques corresponding to the four engine torque pairs at the intersections of the maximum and minimum battery power with the various engine torque limits (Δ) are shown as broken lines (shown in FIG 3 are differently denoted by To (Pbat_max) ₁ , To (Pbat_max) ₂ , To (Pbat_min) ₁ and To (Pbat_min) ₂ ) which further cut the respective battery powers and the corresponding engine torque limits.

As a final step before iteration or before releasing from the block set 220 saves the block 228 subsequently, as described, all the output torques associated with the valid intersections for further use in a decision process described below.

Now in addition by means of 16 the block decides 234 below among the several just-calculated output torques To (Pbat_max) _n and To (Pbat_min) _n and To_max_TaTbTi, in order to determine a maximum output torque therefrom. The selected maximum torque from this decision is To (Pbat_max) ₂ in the present example so that To_max_PbatTaTb is set to it. Subsequently, the block distinguishes 235 among the several calculated output torques To (Pbat_max) _n and To (Pbat_min) _n as well as To_min_TaTbTi. The selected minimum torque from this decision is To_min_TaTbTi in the present example so that To_min_PbatTaTb is set to it. This result is evident in 16 to see.

In 13 Now, a series of processes for determining output torque limits taking into account battery power limitations and engine torque limitations are illustrated. Especially with regard to the blocks 250 . 252 . 286 and 270 This makes it the iterative execution of the justification 254 allows. The justification 254 is performed once for each of the maximum and minimum battery power limit combinations (Pbat_max and Pbat_min) and the maximum and minimum engine based input torque limits embodied in the input torque limit (Ti_max and Ti_min).

wobei Ti gleich Ti_max oder Ti_min, wie es in Übereinstimmung mit den Maschinen- oder Motordrehmoment-Grenzwerten berechnet oder bestimmt wird; und
Ta der bekannte Maschinendrehmomentpunkt ist.In accordance with the block 256 out 13 For example, a plurality of key engine torque combinations or pairs (Ta, Tb) corresponding to the minimum and maximum input torque (Ti_max and Ti_min) calculated by the model in accordance with the engine or engine torque limits are determined. The arrangement of the model is here as in relations (5) and (6), which are here again expediently repeated and correspond to the scenarios with known Ta and with known Tb:

where Ti equals Ti_max or Ti_min as calculated or determined in accordance with the engine or engine torque limits; and
Ta is the known engine torque point.

wobei Ti gleich Ti_max oder Ti_min, wie es in Übereinstimmung mit den Maschinen- oder Motordrehmoment-Grenzwerten berechnet oder bestimmt wird; und
Tb der bekannte Maschinendrehmomentpunkt ist.Similarly:

where Ti equals Ti_max or Ti_min as calculated or determined in accordance with the engine or engine torque limits; and
Tb is the known engine torque point.

Two of the key engine torque combinations or pairs (Ta, Tb) correspond to the intersection of each of the respective Ti_max or Ti_min with the engine torque limit in Ta-Tb and the other two preferably correspond to the intersection of each of the respective Ti_max or Ti_min with the engine torque zero limit in Ta -tb. Thus, each of these intersections provides one of the engine torques for the model to calculate the other of the two engine torques and complete the respective pair. Where a known zero Ta-Tb intersection occurs beyond the other engine torque limit, an alternative point, e.g. For example, a Ta or Tb established by substituting a value substantially midway between the two immediately adjacent Ta-Tb pairs may be replaced. Exemplary key combinations for the illustrated Ti_max are in 17 clearly illustrated and labeled differently with P9-P12. In the block 258 These pairs of engine torque will then be used in conjunction with the above-derived relationship ( 16 ) is used to estimate the battery power in these combinations.

In the block 260 Subsequently, a judgment is made with respect to the maximum and minimum battery power Pbat_max and Pbat_min and the estimated battery power associated with each of the key combinations P9-P12. Neighboring the estimated battery power at P9-P12 will be e.g. B. is systematically compared to Pbat_max and Pbat_min as follows with respect to the key combinations. P9 <Pbat_max <P10 P9 <Pbat_min <P10 P10 <Pbat_max <P11 P10 <Pbat_min <P11 P11 <Pbat_max <P12 P11 <Pbat_min <P12

Where Pbat_max or Pbat_min intersect the maximum input torque Ti_max between the battery power associated with the key combinations, it is assumed that the respective battery power limit (Pbat_max or Pbat_min) exceeds the allowable system torque space in Ta-Tb as represented by the engine torque limits Ta_max, Ta_min, Tb_max , Tb_min and set by the input torque limit values Ti_max and Ti_min, further restricts. Additionally based on 17 It can be seen that Pbat_max (Δ) intersects Ti_max between P11 and P12. Similarly, it can be seen that Pbat_min (Δ) intersects Ti_max between P9 and P10.

It is desirable to calculate the output torque at the intersections of Pbat_max and Pbat_min with Ti_max and Ti_min for further use in the final determinations of the total output torque limits, given the engine, engine and battery limitations. In accordance with the use of the model for setting the output torque, at least one of the engine torques Ta or Tb is required at the intersections. Thus, in the block 262 a linear estimation, interpolation, section search or other suitable technique based on the known Ta-Tb pairs at the estimated battery powers P9-P12 is used to set the required engine torque points corresponding to the intersection points.

wobei Ti gleich Ti_max oder Ti_min, wie es in Übereinstimmung mit den Maschinen- oder Motordrehmoment-Grenzwerten berechnet oder bestimmt wird; und
Ta der bekannte Maschinendrehmomentpunkt ist.The step 264 shows that subsequently, the output torque at the intersections (Δ) is calculated using the model and second known torques from the intersection, preferably the restricted input torque Ti_max (or possibly Ti_min) and the determined one of Ta and Tb corresponding to the intersection. Thus, the arrangement of the model takes on the familiar form of relations (5) or (6), which in the following are expeditiously repeated below and correspond to the known Ta or Tb scenarios:

where Ti equals Ti_max or Ti_min as calculated or determined in accordance with the engine or engine torque limits; and
Ta is the known engine torque point.

wobei Ti gleich Ti_max oder Ti_min, wie es in Übereinstimmung mit den Maschinen- oder Motordrehmoment-Grenzwerten berechnet oder bestimmt wird; und
Tb der bekannte Maschinendrehmomentpunkt ist.Similarly:

where Ti equals Ti_max or Ti_min as calculated or determined in accordance with the engine or engine torque limits; and
Tb is the known engine torque point.

Additionally again on the basis of 18 In the present example, the output torques calculated in the present example, after the execution of the entire iteration, corresponding to the intersections (Δ) of the maximum and minimum battery power with the maximum input torque are shown as broken lines (different from To (Pbat_min, Ti_max) ₁ and To (Pbat_max, Ti_max) ₁ ), which further cut the respective battery powers and the corresponding engine torque limits.

As a final step before iteration or before releasing from the block set 254 saves the block 266 subsequently, as described, all the output torques associated with the valid intersections for further use in a decision process described below.

Now in addition by means of 19 the block decides 274 below among the plurality of just-calculated output torques To (Pbat_max, Ti_max) _n , To (Pbat_max, Ti_min) _n , To (Pbat_min, Ti_max) _n , To (Pbat_min, Ti_min) _n and To_max_TaTbTi to determine a maximum output torque therefrom. The selected maximum torque from this decision is To (Pbat_max, It_min) ₁ in the present example, so that To_max_PbatTi is set to it. This result is evident in 19 to see. Subsequently, the block distinguishes 275 Among the several just-calculated output torques To (Pbat_max, Ti_max) _n , To (Pbat_max, Ti_min) _n , To (Pbat_min, Ti_max) _n , To (Pbat_min, Ti_min) _n and To_min_TaTbTi. The selected minimum torque from this decision is To_min_TaTbTi in the present example, so that To min PbatTi is set to it. This result is evident in 19 to see.

Now, at the output torques, which are considered the maxima and minima with respect to the various based on the schedules of the 6 . 12 and 13 have been determined, carried out a final decision. In 20 For example, the maximum output torques (To_max_TaTbTi, ToMax_Pbat_TaTb and To_max_PbatTi) are supplied to the MIN function block to determine the most limited value, with the selection being supplied as To MAX. Similarly, the minimum output torques (To_max_TaTbTi, ToMax_PbatTaTb, and To_max_PbatTi) are provided to the MAX function block to determine the most constrained value, with the selection being supplied as To_MIN.

Although the invention with reference to certain preferred embodiments and implementations described could have been of course within the spirit and scope of the invention described innovative concepts numerous changes are made. Accordingly, the invention should not be limited to the disclosed embodiments limited but have the full scope of the formulation of the following claims allows.

Claims (18)

Method for determining output torque limits in a vehicle powertrain, a motor, an electrically variable transmission that at least contains an electric motor, and a powertrain, wherein the engine is functional with a Input of the electrically variable transmission is coupled, wherein The powertrain is functional with an output of electrically variable Gearbox, the method comprising: Determine a permissible one Motor torque operating space; Determine input torque limits within the allowable electric motor torque operating space; Determine electric motor torque limits at the input torque limits; and Determining Output Torque Limits Based on Input torque limit values and the motor torque limit values. Method for determining output torque limits according to claim 1, wherein the permissible Motor torque operating room is determined so that in the at least one electric motor Torque capacity reservation is created. Method for determining output torque limits according to claim 1, wherein the input torque limit values based the engine torque limits and the motor torque limits the permissible Motor torque operating space be determined. Method for determining output torque limits according to claim 1, wherein the determined electric motor torque limits in the Input torque limits are the least limited output torques correspond. Method for determining output torque limits in a vehicle powertrain, a motor, an electrically variable transmission that at least contains an electric motor, and a powertrain, wherein the engine is functional with a Input of the electrically variable transmission is coupled, wherein The powertrain is functional with an output of electrically variable Gearbox, the method comprising: Determine of input torque limits as the most restricted of the Input torques, the specified motor torque limits and predetermined electric motor torque limits; Determine, which of the predetermined electric motor torque limits at the input torque limits the least restricted Corresponds to output torques; and Determining output torque limits based on the input torque limits and the given motor torque limits, those at the input torque limits the least restricted Output torques correspond. Method for determining output torque limits according to claim 5, wherein the engine torque limits in accordance be determined with a set of engine operating parameters. Method for determining output torque limits according to claim 6, wherein the engine torque limit values are stored from records be determined in a control unit. Method for determining output torque limits according to claim 6, wherein the engine torque limits in a control unit be determined in real time. Method for determining output torque limits according to claim 5, wherein the electric motor torque limits in accordance determined with a set of electric motor operating parameters become. Method for determining output torque limits according to claim 9, wherein the elec tromotor torque limits are determined from stored data sets in a control unit. Method for determining output torque limits according to claim 5, wherein the electric motor torque limit values so be determined that in the at least one electric motor Reservation of torque capacity is created. Method for determining output torque limits in a vehicle powertrain, a motor, an electrically variable transmission that at least contains an electric motor, and a powertrain, wherein the engine is functional with a Input of the electrically variable transmission is coupled, wherein The powertrain is functional with an output of electrically variable Gearbox, the method comprising: Determine least restricted limited by the electric motor input torques, the predetermined Electric motor torque limits correspond; Determine from by the motor limited input torques, the predetermined Motor torque limits correspond; Select from Input torque limits as the most restricted of the by the electric motor limited input torques and by the motor limited input torques; and Determine from Output torque limits as the least restricted of the Output torques corresponding to the input torque limits and corresponding to the predetermined motor torque limit values. Method for determining output torque limits according to claim 12, wherein the engine torque limits are in accordance be determined with a set of engine operating parameters. Method for determining output torque limits according to claim 13, wherein the engine torque limit values are stored from records be determined in a control unit. Method for determining output torque limits according to claim 13, wherein the engine torque limits in a Control unit can be determined in real time. Method for determining output torque limits according to claim 12, wherein the electric motor torque limits in accordance with a set of electric motor operating parameters be determined. Method for determining output torque limits according to claim 16, wherein the electric motor torque limits stored records be determined in a control unit. Method for determining output torque limits according to claim 12, wherein the electric motor torque limit values so it is determined that in the at least one electric motor a reservation of torque capacity is created.